1. Field of the Invention
This invention relates to an apparatus for recognizing and approaching a target in a space which is not directly visible, whereby a rotating camera on the end of a boom of an industrial robot observes the environment of the boom and sends images to a monitor at a remote control station.
2. Description of the Prior Art
Industrial robots are manually remote-controlled movement devices for performing manipulation tasks. They are frequently used if the manipulation tasks must be performed in areas which are not visible or inaccessible to human beings, and may include, for example, the inside of the pressure vessel of a radioactive nuclear reactor. In connection with the present invention, the term "industrial robot" is also used to mean an occasionally manually-controlled industrial robot (VDI Guideline 2860, Sheet 1, 1982 Draft Edition, Paragraph 5.1.1).
It is known that industrial robots can be controlled by means of images from cameras mounted on boom arms ("Industrial Robots", Pergamon Press, Oxford, UK, Page 90, corresponding Japanese Patent No. 52.91265). However, it appears that the type of camera movement and the method of controlling the axes of the industrial robot was not disclosed therein.
The publication "Sensor Review", January 1983, page 23-26, also describes an anthropomorphic robot with a camera located on the tool head parallel to a gripper. However, no images are taught to be transmitted for a manual remote control since the disclosure is, instead, directed to parallax-free pattern recognition.
Great Britain Patent No. 2 087 107 describes an industrial robot of a cylindrical type, which has a camera on the tool head. Using the "teach-in" method by the industrial robot, a three-dimensional weld seam can be produced, read in, and inspected by the camera. It does not appear that a direct approach to a three-dimensional target is an object of the patent.
U.S. Pat. No. 4,258,425 describes a cartesian-type robot, which can be remotely controlled manually, on rails or in the playback mode. Although the coordinates are displayed on a screen, there does not appear to be any camera guidance or point-target control.
On a remote-controlled, off-road manipulator vehicle ("Kerntechnik", 1975, Volume 12, Page 527-532), there are mono and stereo television cameras for optical control and inspection on the vehicle in a pivoting and tilting head. The camera position is not optimized for a precise, targeted guidance of the tool head or gripper, since the manipulator arm or the track might conceal the working positions of the gripper. It also fails to include a combined multi-axis control of the gripper.